The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Heat transfer fluids (e.g., refrigerants) are commonly used in various heat transfer systems, including air conditioning, refrigeration, freezers, heaters, and the like. Many formulations for heat transfer fluids are known.
At the time this application is filed, R22 (cholordifluoromethane) is being phased out in many developed countries due to its ozone depletion potential (ODP) and high global warming potential (GWP). There is currently a need for new compositions of heat transfer fluids that can serve as a replacement for R22 and that have improved ODP and GWP.
Various heat transfer compositions are described in WO2011/077088, AU2007338824, US20070284078, U.S. Pat. No. 6,511,610, U.S. Pat. No. 6,521,141, and RU2135541. Unfortunately, heat transfer fluids that are currently available suffer from one or more disadvantages when used as a substitute for R22.
Various R22 replacement compositions are described in Retrofit Handbook, “R-22 Retrofit Guidelines and Procedures” (2009) by NRI™. Suitable R22 replacements preferably have similar or better performance metrics (e.g., heat absorption capacity, latent heat of vaporization, amperage, pressure differential, operational temperatures, cycle time, etc.) and better ODP and GWP than R22. Replacement compositions also preferably carry mineral oil (e.g., mineral oil is miscible in the heat transfer fluid) so that the replacement fluid can be used with R22-based heat transfer systems that currently use mineral oil as a lubricant. In addition, replacement compositions preferably have low flammability levels that meet industry standards and governmental regulations.
All publications identified herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
Thus, there is still a need for improved heat transfer fluids, systems, efficiencies and methods.